Patent GB-687061-A (GB)
Title: Hydraulic control systems particularly for use in automatic washing machines
IPC: D06F33/08
Filed: 1948-04-26
Abstract: 687,061. Washing-machines. ROBERTSHAW-FULTON CONTROLS CO. April 26, 1948 [June 3, 1947] No. 11370/48. Class 138 (ii). A hydraulic control system for a washing-machine having a plurality of elements to be controlled comprises a pressure motor for each element, each pressure motor including an expansible and collapsable chamber situated within a second chamber with which the first chamber is in communication through a bleed opening, outlet passages individual to and communicating with one chamber of each pressure motor, means for admitting liquid under pressure to the other chamber, means providing a low pressure passage 110 and a single pilot valve 17 associated with all of the outlet passages and including means for sequentially bringing the same into communication with the low pressure passage. The elements to be controlled include flow control valves 12 and 20, and a mixing valve 14, and in each case the expansible and collapsable chamber may comprise a corrugated tubular wall or bellows. Hot and cold water are supplied to the mixing valve 14 through nipples 15, 16 and thence to the flow control valve 12. Valve 12 is operated by fluid pressure, partly under the control of a float valve 13 in or associated with the tub of the washing machine. The admission of water to the tub is under the control of the pilot valve 17 which is operated by timing mechanism shown in Fig. 3. Associated with the driving shaft 10 of the washing machine is a balancing valve 18 which is operatively associated with a brake operator 19 for operating a brake associated with mechanism for determining when spin-drying shall commence. Valve 18 and operator 19 are controlled by the valve 20 which in turn is controlled by a pressure operated valve 21 in the line connecting the valves 17 and 20. The valve 21 is in turn controlled by fluid pressure devices, such as 22, associated with the legs of the washing machine and which develop a pressure for operation of the valve 21 in the event of a predetermined condition of unbalance of the machine. A main drain valve operator 23 is also controlled by the pilot valve 17. Mixing valve 14 (Fig. 2, not shown). The construction of this valve is identical with that described in Specification 687,060, except for the provision of a bleed opening in the, bellows 68 inside a top member 56. The mixing valve supplies water at a constant pre-determined temperature for washing, so long as water leaking through the bleed opening is free to flow out through the passage 80. However, if the passage 80 is closed the valve operates to supply predominately cold water for the rinsing operation. Flow control valve 12 (Fig. 1). The washing or rinsing water from the mixing valve 14 flows through a conduit 86 to the valve 12 described in greater detail in Specification 687,060. It includes a casing 88 with an outlet 11 to the washing machine tub, the outlet 11 being controlled by a valve member 90. The member 90 is carried by one end of an expansible and collapsible bellows 93 whose other end is attached to an end wall of the casing 88. The bellows chamber is in communication with the chamber in casing 88 through a bleed opening 95 in the bellows 93, and with the pilot valve 17 through a conduit 97. Float controlled valve 13 (Fig. 1). A float 100 is connected through a pivoted lever 101 to a valve member 108 carried by the movable end wall of a bellows 103 secured to a fixed block 104 having passages 105, 106 leading from the chamber inside the bellows. Valve member 108 co-operates with a valve seat at the end of passage 105 which is connected by a conduit 109 with pilot valve 17. Passage 106 is connected to the low pressure passage 110 leading to the drain connections. Balancing valve 18 (Fig. 1). This valve includes a ring 112 of suitable elastic or resilient material surrounding the driving shaft 10, the ring 112 being compressible under eccentric motion of the shaft to permit flow of water therepast at 180 degrees from the point of compression. The ring is retained in position by a surrounding part 113 of a casing 114. This casing is connected by a conduit 115 with the casing 116 of a Brake Operator 19 (Fig. 1) which is as described in Specification 687,060. A tubular bellows 117 is connected at one end to the casing 116 and at the other end to a stem 119 connected to a brake which controls the spinning of the tub. Pressure in the casing 116 moves the stem 119 to the right to release the brake and initiate spinning, whereas when pressure is released the bellows 118 or a spring associated therewith returns the stem to the left so as to apply the brake and prevent spinning. Flow control valve 20. This valve determines the pressure in the balancing valve casing. It comprises a bellows 125 secured at one end to a casing 122 having a valve port 123 in communication with the casing 114. The movable end of the bellows carries a member 128 for co-operation with the port 123. The casing 122 has an inlet 129 connected to a source of water, e.g. the cold water line leading to nipple 16. The bellows 125 includes 'a bleed opening 131. Pressure operated valve 21. This valve includes a casing 140 and is connected to valve 20 through an outlet 132 and valve casing 133 with which communicates a conduit 134 leading to the pilot valve. Inside casing 133 is a valve member 135 mounted so that it may open and close the inlet 136 to conduit 134. This member 135 is mounted on a stem 137 secured to the movable end wall of a bellows 139 whose opposite end is secured to the casing 140. The movable end wall has a flange 141 slidably mounted in the casing 140 and acted on by a coil spring 142 so as normally to urge the valve member 135 into a position wherein the inlet 136 is open. Casing 140 has an end wall 143 in which is a valve port 144 having a flap valve 145. A ring 146 secured to the wall of the casing is provided with a radially extending resilient arm 147 carrying the flap valve 145. Valve 145 may be provided with a bleed opening or its engagement with the port 144 is such as to provide a predetermined leakage. Port 144 is connected by a conduit 149 to interconnected pressure devices 21 associated with the legs of the machine. Each device 21 includes a foot 150 adapted to rest on the floor, an upwardly extending part 151, and a plunger 152 in a cylinder 153 having, e.g. nuts 154 for attachment to a leg of the machine. The several cylinders 153 are interconnected by pipes 156. During washing, the pilot valve 17 closes the outlet of passage 134 so that water entering the casing 122 flows through bleed opening 131 and equalizes the pressure on opposite sides of the bellows 129. The bellows therefore because of its inherent resiliency moves valve member 128 to close the port 123 until the end of the washing cycle when the pilot valve 17 opens the outlet 134 so that pressure inside the bellows is released. The pressure of water entering at 129 thus compresses bellows 125 to open port 123, and then compresses bellows 117 to release the brake to commence the spinning operation. Drain valve operator 23 (Fig. 1). This includes a casing 160 in which is an expansible and collapsable chamber from the movable wall of which extends a stem 161 for connection to and operation of a main drain valve. The chamber in casing 160 communicates with a conduit 162 leading to the conduit 134 and pressure is maintained at operator 160 to keep the drain valve closed until the end of the washing cycle. Timing mechanism (Fig. 3). The armature 167 of an electric motor 165 is mounted to rotate freely on a shaft 168 which extends outside a casing 166 and carries a knob for manual rotation so that one or more of the stages in the washing process may be skipped. The armature of the motor has a hub 169 on which is a pinion 170. Meshing with the pinion 170 is a planetary gear 171 which also meshes with a stationary ring gear 172 secured to the casing 166. The stub shaft 174 of gear 171 is carried by a disc 175 rotatably mounted on the shaft 168. The drive continues through pinions 176, 180, 184 planetary gears 177, 181, 185, and discs 179, 183, 187. Disc 187 carries a cam member 189 on its hub 188 (Fig. 5), a nose 193 on the cam co-operating with a cam faced opening 190 in a lever 194 pivoted at 191. Opening 190 has two steps 192 and is urged by any suitable spring into contact with the cam member '189. Thereby at each revolution of member 189, lever 194 is oscillated twice about its pivot, and a pawl 195 pivoted on the lever 194 is actuated once to advance a ratchet wheel 197 the distance of one tooth. The pawl 195 is urged by a spring towards the ratchet wheel 197 and prevents manual rotation of the shaft 168 in the reverse direction. The knob for rotating the shaft may be associated with suitable means for indicating the various stages in the operation of the machine. Shaft 168 is also provided with means for actuating the control means for the motor 165 and also for the main motor which drives the washing machine, this means being of the type described in detail in Specification 687,060, [Group XXIX], (see Fig. 4, not shown). Pilot valve 17 (Figs. 1 and 3). This valve includes a casing 213 having an opening 214 at its end adjacent to the casing 166 while its opposite end is closed by a plate 215. Plate 215 has an outlet nipple 217 leading to any suitable low pressure conduit such as a passage leading to the drain connections. Rotatably mounted inside the casing 213 is a cylindrical body 220 operatively connected to the ratchet wheel 197 as by a pair of pins 222. The casing 213 has a suitable number of ports 225 leading to a number of circumferentially extending passage systems, each including one or more grooves of suitable length and locating for registry with the corresponding ports at suitable times during the rotation of the body 220. These passage systems are shown in detail in Figs. 6 to 12 (not shown). Operation. After determining the te